diff --git a/app/assets/javascripts/discourse/app/lib/utilities.js b/app/assets/javascripts/discourse/app/lib/utilities.js
index b6cbf19ef2a..aae661e00ec 100644
--- a/app/assets/javascripts/discourse/app/lib/utilities.js
+++ b/app/assets/javascripts/discourse/app/lib/utilities.js
@@ -169,7 +169,13 @@ export function selectedText() {
   div
     .querySelectorAll("div.video-placeholder-container[data-video-src]")
     .forEach((element) => {
-      element.replaceWith(`![|video](${element.dataset.videoSrc})`);
+      const videoBase62Sha1 = element.dataset.videoBase62Sha1;
+      if (videoBase62Sha1) {
+        element.replaceWith(`![|video](upload://${videoBase62Sha1})`);
+      } else {
+        // Fallback for old posts that don't contain data-video-base62-sha1
+        element.replaceWith(`![|video](${element.dataset.videoSrc})`);
+      }
     });
 
   return toMarkdown(div.outerHTML);
diff --git a/lib/pretty_text.rb b/lib/pretty_text.rb
index 03b7ee3cd4a..e73e0af4499 100644
--- a/lib/pretty_text.rb
+++ b/lib/pretty_text.rb
@@ -460,6 +460,9 @@ module PrettyText
           video["data-thumbnail-src"] = UrlHelper.absolute(
             GlobalPath.upload_cdn_path(thumbnail.url),
           )
+          video[
+            "data-video-base62-sha1"
+          ] = "#{Upload.base62_sha1(video_sha1)}#{File.extname(video_src)}"
         end
       end
   end
diff --git a/lib/pretty_text/helpers.rb b/lib/pretty_text/helpers.rb
index a20d77decee..7185ec27622 100644
--- a/lib/pretty_text/helpers.rb
+++ b/lib/pretty_text/helpers.rb
@@ -45,7 +45,10 @@ module PrettyText
       urls.each do |url|
         sha1 = Upload.sha1_from_short_url(url)
         if (url.split(".")[1].nil?) # video sha1 without extension for thumbnail
-          thumbnail = Upload.where("original_filename LIKE ?", "#{sha1}.%").last
+          thumbnail = Upload.where("original_filename LIKE ?", "#{sha1}.%").last if sha1
+          # Fallback for old posts that don't contain data-video-base62-sha1
+          thumbnail = Upload.where("original_filename LIKE ?", "#{url}.%").last if thumbnail.nil? &&
+            sha1.nil?
           sha1 = thumbnail.sha1 if thumbnail
         end
         map[url] = sha1 if sha1
diff --git a/spec/lib/pretty_text_spec.rb b/spec/lib/pretty_text_spec.rb
index 2dc974a3e09..819c1832188 100644
--- a/spec/lib/pretty_text_spec.rb
+++ b/spec/lib/pretty_text_spec.rb
@@ -2819,8 +2819,10 @@ HTML
       doc = Nokogiri::HTML5.fragment(html)
       described_class.add_video_placeholder_image(doc)
 
+      video_base62_sha1 = "#{Upload.base62_sha1(@video_upload.sha1)}.#{@video_upload.extension}"
+
       html_with_thumbnail = <<~HTML
-        <p></p><div class="video-placeholder-container" data-video-src="#{@video_upload.url}" data-thumbnail-src="http://test.localhost#{thumbnail.url}"></div><p></p>
+        <p></p><div class="video-placeholder-container" data-video-src="#{@video_upload.url}" data-thumbnail-src="http://test.localhost#{thumbnail.url}" data-video-base62-sha1="#{video_base62_sha1}"></div><p></p>
       HTML
 
       expect(doc.to_html).to eq(html_with_thumbnail)